Escapement mechanism



Sept. 16

G. AICHELE ESGAPEMENT MECHANISM Filed Jan. 23

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wheel meshing with-a rank 6." The latter Patented Sept. l6, 1 924.

GOTTLOIB AICHELE, OF NELLINGEN, NEAR ESSLINGEN, GARY.

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Application filed January 23, 1924. Serial No. 687,908.

have invented certain new and useful Im-- provements in an Escapement Mechanism, of which the following is a specification? This invention relates to a mechanical move ment commonly termed an escapement for use in connection with typewriting machines and intended to produce progressive intermittent motion of the carriage with the platen or paper roller by the forward and the backward movement of the type-bars. The means employed for the purpose comprises primarily a divided controlling gearwheel and a dog or control-knife cooperating with the parts of said wheel; the characteristic features of these parts reside therein that the opposite faces of the teeth of the controlling-wheel halves and of the faces of the dog cooperating with said tooth-faces are oblique, in such'a manner, that jerky movements of the cooperating parts are obviated and onl sliding motion is obtained. As a result 0 this, a uniform smooth feed of the carriage is provided'and the noise resulting from such jerky motion is obviated. The dog is reciprocated in accordance with the operation of the type-bars and moves from one gear-wheel part to the opposite gearwheel part in harmony with the movements of the type-bars toward and away from the platen of the paper-carriage.

My invention is illustrated by way of example in the accompanying drawing in which Figure 1 is a vertical section through the escapement, showing the combination and arran ement of parts forming the new mechanica movement, some of the parts being shown in side-view, Figure 2 is a front view of the device, partly in vertical section, and Figures 3-8 are diagrammatic illustrations showing, on an enlarged'scale, the various positions of the halves of the controlling gear-wheel and of the operating dog relatively to one another, as is all fully described hereinafter.

The upright standard a is provided at its upper part with two "bearings a and a carrying centres b b which support a short horizontal shaft 0 on which is secured a cogmeshes also with a cog-wheel f connected with, or forming part of, a box g enclosing a spiral spring whereby the carriage, is propelled in one direction in successive steps.

- The shaft 0 supports the bipartite controlling gear-wheel h, i; the half h is,

capable of being rotated on this shaft, but

the half '5 is aflixed thereto by a screw 70. The wheel-halves 72. and i are coupled with each other by'projections bland 6', formed on the gear-sections h and '5 respectively and overlapping each other in spaced relationto form a gap 1 as shown by dotted lines in Fig. 1. The said halves are so shaped that a space is left, or a chalnlqer is formed between them, in which space or chamber a spiral spring m islocated'; one end of this spring is connected at the point 'm/ with the wheel-half lb, the other atthe point m with the wheel half '5. The spring m exerts a tension whereby the gear sections it and z quence as the mechanism is operated.

The dog a is carried by a double-armed lever 0, 0 made integral with pivots 0 o, and supported between centres p, p. The lever-arm 0 has a slot 0 in which a slide 9 connected with a rod q, may be adjusted and fixed. The dog a is so arranged as to swing upon a pivot n and is subjected to the upward pressure of a bolt n which itself is pressed upwardly by a spiral spring w. The ivotal upward movement of the dog n s, owever, limited by an abutment lug a.

The double-armed lever 0, o is oscillated by means of the reciprocating rod 9 which is actuated, for instance, by the controlbridge (not shown) of the typewriting ma chine. r is a spiral spring which encompasses the pivot o of the lever o, 0 and is prevented from leaving its place by a collar 0 of said pivot 0 the spring 9 tends constantly to hold said lever in the position shown in Figure 1. An adjusting screw 8 is located on the arm oof the lever o, o for arresting the throw thereof in one d1- rection. I

The upper end of the dog a cooperates alternately-with a tooth of the gear wheel section it and with a tooth of the gear wheel section 2'. The shape of the teeth of the gearwheel sections h and z' is shown in Figures 3-8 on an enlarged scale, there be ng shown in each of these figures three teeth of the are progressively rotated in alternate s'ewheel-half h and three teeth of the wheelhalf 71. In the operation of the machine, the dog 1?. is moved alternately from hto z' and from i to h, and thus brings about a step by step progression of the bipartite gear hz'. An essential feature lies in-the shape of the dog and of the teeth, in that the operating end of the dog, i.,e. the end cooperating with the teeth of the two wheel halves, is triangular in horizontal cross-section as shown in the Figures 3-8, and the end faces of the gear-wheel halves, i. e. their opposite end-faces lie in transversely arranged planes or are cut off obliquely in opposed relation as shown, for instance, in Figures 4 and 7.

Supposing, a type-bar is being moved toward the paper roller or platen so as to print its character upon the paper running around the roller, the dog a (Fig. 3) which at the time contacts with the tooth m of the gear-wheel half a is moved tothe right, along the tooth on, by means of the rod-g and the lever 0, 0 and at the middle point of its path, is located at the oblique endface of the tooth m (Fig. 4:); from this point the dog n passes over to the tooth g of the gear-wheel half b. As soon as the dog n has left the tooth a", the wheel half 71 is rotated slightly in the direction indicated by the arrows between the Figures 3 and 4, 4 and 5, 6 and 7, and 7 and 8; this is accomplished by means of the spring m located within the ear-wheel h, i, or between its halves respectlvely, as already described. The extend of this rotary motion is such that the tooth 0a, which occupied the position indicated by dotted lines in Fig. 5 when its oblique end-face and the oblique face of the dog n were in registering surface engagement with each other, shifts to the posi tion shown in full lines in Figure 5 in which the dog has reached the end of its movement to the right. The position of the parts shown in Figure 6 is the same as in Figure 5, the only difference being that the dog a is now about to move in the reverse direction, which reverse movement begins when the type bar just used commences to move. away from the paper, or the paperroller respectively, in a return movement toward its positions of rest. The reverse direction is indicated by the horizontal arrow below the designation Fi 6. Similar arrows indicating the direction of movement of the dog appear also below the designations fFig. 3, Fig. 4, Fig. 5, Fig. 7, Fig.8. The dog n now move along the/tooth 3 until it arrives atthe oblique end-face thereof. *While the oblique faces of n and :1 move along one another, the gearwheel half It is turned by the spring m in the direction indicated by the vertical arrow (Fig. 7 and the dog contacts finally with the tooth as of the gear-wheel half 2'. The dog '11, now glides along this tooth (Fig. 8)

- versely arranged asoaeoe until it arrives in its lefthand end-position, whereupon the succession of operative ste in the direction from the left to the rig t (Figs. 3-5) is repeated,,and so on. At this stage, however, the next tooth of h, viz. 3 will cooperate with the dog, and also when the latter repeatsnits path from the right to the left, the next tooth of i will cooperate therewith, and so on. As the dog a oscillates back and forth the oblique end surfaces of the teeth of the gear sections it and 2' will successively glide along the inclined faces of the dog in smooth, uniform move ments free from jerks; the step by step operation of the escapement is thus devoid of shocks and is accomplished with a minimum of noise.

I claim: 1

1. A mechanical movement for the production of progressive intermittent movement of the paper-carriage by the to-and-fro movement of the type-bars, comprising, in combination, two co-axial cog-wheels arranged side by side and having teeth with oblique end-faces projecting toward each other and lying in close proximity to one another; a movable dog having a triangular opfrating end, the opposite active faces of; w ich are parallel to said end-faces and! adapted to cooperate alternately with one and the other of said wheels and means for reciprocating said movable dog, substantially as described.

2. In a typewriter, an escapement comprising a plurality of coaxial gears, a movable. dog cooperating with said ears to produce a step by step feed thereo the cooperating surfaces of said dog and the teeth on said gears being correspondingly inclined and arranged to slide along each other during the movement of the dog to provide a gradual rotation of said gears in the feeding steps thereof and means for actuating said In a typewriter; an escapement comprising a pair of coaxial gear wheels in surface parallelism with each other, the teeth of which project toward each other and have their inner end faces in transin the direction 0 the common axis of said gear wheels and adapted to pass from one gear wheel to the other, said dog having surfaces slidingly cooperating with said inner end surfaces of said teeth in the passage fronr one gear wheel to another to permit a gradual rotation of said wheels in successive steps and means for operatfhg said dog. I

4:. In a typewriter, an escapement comprising a pair of coaxial. gear wheels, the teeth of which project toward and beyond each other, the end faces of said teeth being oblique to their length, a dog reciprocable in the direction of the common axis'of said planes, a dog reciprocable Nil gear wheels and slidable 010351 the teeth of In testimon whereof I aflix my signature one on to the teeth of the er, said d in presence 0 two witn.

having inclined surfaces cooperating wit j the end faces of said teeth, in the passa GOTTLOB AICHIELE.

- 5 from one gear wheel to another to enn Witnesses:

gradual rotation of said wheels in successive H. Umnm, steps and meansfor vibrating'said dog; 0. Jr. 

